JP-A-9-29996 discloses an image forming apparatus which forms an image by ejecting ink drops. In order to prevent ink in nozzles from increasing in viscosity or drying, the image forming apparatus performs a flushing operation in which ink are ejected regardless of image formation or a micro-vibrating operation in which micro-vibrations are given to inks in nozzles by driving an ejection actuator in such a degree that inks are not ejected from the nozzles.
However, the flushing operation consumes inks wastefully and consumes time since it is necessary for a recording head to move to a position which receives inks ejected in the flushing operation. On the other hand, the micro-vibrating operation does not consume inks wastefully. However, in the micro-vibrating operation, the ejection actuator and a drive circuit thereof are heated since it is necessary to drive the ejection actuator by a number of times in order to give a number of times of vibrations to ink in order to obtain an effect of preventing ink from increasing in viscosity or drying. Therefore, not only the durability of the ejection actuator and drive circuit may become worse but also the ejection performance may become worse due to the heat.